Vent and inlet for gas heater



United States Patent VENT AND INLET FOR GAS HEATER 4 Claims, 2 Drawing Figs.

US. Cl 126/85, 165/48 Int. Cl. F25b 29/00 Field ofSearch 165/47, 48, 50, I22; l26/85,9l

References Cited UNITED STATES PATENTS 3,395,693 8/1968 Cowan l26/85' FOREIGN PATENTS 676,829 8/l952 Great Britain 126/85 Primary Examiner- Robert A. O'Leary Assistant l-lraminer-Charlcs Sukalo Attorney-Cushman. Darby and Cushnmn ABSTRACT: A gas wall heater of the type having an ambient air inlet and an exhaust gas vent extending through a building wall and a sealed combustion chamber disposed adjacent the wall. The inlet and vent openings are specially constructed and arranged within a common louvered chamber which is open to the atmosphere through the outside surface ofthe wall and which is substantially flush with the wall. in the preferred construction the heater is combined with a compression type air conditioner, and the refrigerant condenser portion of the Wilhoite l 6 5/4S latter is also disposed in the chamber.

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3,530,848. Patented Sept. 29, 1970 l/ll] zdma mm g4! ATTORNEYS VENT AND INLET FOR GAS HEATER This invention relates to gas fired space heaters of the type including sealed combustion chambers and in particular to wall-mounted heaters which are provided with a gravityoperated air inlet and exhaust gas vent extending horizontally through the wall.

lt is desirable from the standpoint of appearance when employing a heater of the above-described type to avoid horizon tal chimney projections and particularly so in motel or other plural building units where a series of projections would be quite unsightly. In addition, the absence of projections is desirable from the standpoint of safety and convenience, because there are no obstructions which can be run into.

It is the principal object of the invention to provide a combined air inlet and vent arrangement of improved construction which does not project appreciably beyond the outer wall surface yet which effects counter flow of combustion air and exhaust gases without mixing of the two. This combination of features is not readily obtained in a gravity flow system, because once the inlet opening and outlet opening are disposed within the profile of a building wall, as they must be to obtain a flush arrangement, there are encountered unpredictable air and exhaust gas currents which may adversely affeet the operation of the heater. For example, there may be a tendency for the exhaust gas to mix with the inlet air thereby lowering the efficiency of the burner. In addition, the action of wind is apt to create pressure changes which disrupt the air and exhaust flow.

According to the principles of the present invention a flush inlet and vent arrangement is constructed in the form of a horizontally extending combustion air inlet conduit and a horizontally extending vent conduit disposed above the inlet duct and terminating in a common chamber which is open to the atmosphere through the building wall, the open end of each conduit being provided with a distinct axially spaced, generally vertical baffle around which the respective gaseous fluid flows before leaving or entering the respective conduit. in the preferred construction the baffle associated with the vent conduit includes a pipe section of greater diameter than the vent conduit concentrically disposed around the open end of the vent and around the aforesaid vertical baffle so that exhaust gases can flow longitudinally of the vent in either direction after leaving the open end of the vent. The arrangement has particular utility in a combination gas heater and a compression-type air conditioner, because the inlet, vent and condenser portion of the air conditioner can all be disposed within the contours of the building wall. A decorative and functional grille may then be installed flush with the outer surface of the building wall so as to cover all the components of the combination unit.

The invention will be further understood from the following detailed description of an illustrative embodiment in conjunction with the drawing in which:

FIG. 1 is a schematic rear elevational view, partly broken away, of a combined air conditioner and gas wall heater embodying the inlet and vent arrangement of the present invention; and

FIG. 2 is a sectional view taken on th'line 2-2 of H6. 1.

In the drawing there is disclosed in simplified form a combination compression-type air conditioner and gas wall heater incorporating a combustion air inlet and vent arrangement 10 which embodies the principles of the present invention. The improved inlet-vent arrangement 10 has particular utility in the combination unit, because it lends itself to incorporation in a common housing with the enclosed parts of the air conditioner such that the housing can be made flush with the outside surface ofthc building wall. In the illustrated embodiment the common housing is shown in the form of a sleeve 12 of rectangular cross section fitted into an opening through a building wall 14. The outer or rear end of the sleeve 12 is open and is provided with a perforated wall such as a louvered panel 16 which is substantially flush with the outer surface of the wall 16. The inner or forward end of the sleeve 12 is closed as by a vertical partition 17.

The inlet and vent arrangement 10 and a portion of the air conditioner are disposed within the sleeve 12 in side-by-side relationship. The air conditioner may be of any conventional compression type having finned condenser coils 18 or the equivalent and is arranged within the sleeve such that the coils 18 are disposed close to the rear louvered panel 16 and such that the refrigerant evaporator portion is disposed on the forward side of the partition 17.

The details of the air conditioner, including a fan for directing ambient air rearwardly past the coils l8 and through the panel 16, are omitted from the drawing, inasmuch as they form no part of the present invention.

In front of the sleeve, that is, on the inside surface of the building wall 14 there is provided a louvered cabinet 20 which encloses a gas wall heater 22 and the various blowers, duct work and controls by which heated air or conditioned air is passed into the surrounding room, The cabinet 20 may be attached to the wall 14 and/or to the sleeve 12, and it may rest on the floor 24 so that it can support the weight of the heater 22 and the other interior parts. The cabinet 20 and the sleeve 12 can be divided into sub-compartments by either vertical or horizontal portions, as needed.

The heater 22 may be of conventional construction and, as shown, it comprises a hollow sealed combustion chamber of the kind which includes a main combustion chamber 26 and a plenum chamber 26a spaced rearwardly from the main chamber 26 and parallel thereto. A burner tube 28 is arranged in the lower part of the main chamber 26 and a pair of horizontally spaced apart ducts, one of which is shown at 30, connect the upper portion of the main chamber 26 with the plenum chamber 26a. Usually a fan (not shown) will be mounted below the combustion chamber for drawing room air in through the lower openings in the cabinet 20, passing the air upwardly along the combustion chamber and the plenum chamber, and then into the room through the upper openings in the cabinet 20.

All of the above-described features, with the exception of the improved vent arrangement 10, are broadly conventional as shown, for example, in Wilhoit US. Pat. No. 3,326,276, and they are given here in order to establish the environment for the improvement which constitutes the present invention. in this regard, it will be understood that the improved vent arrangement is for use in combination with a heater of the gravity-flow-type, although the details of the combustion chamber may vary.

The improved vent arrangement 10 includes a horizontal vent conduit 32 for conducting combustion gases from the gas heater 22 and a horizontal air supply conduit 34 for conducting combustion air to the heater 22. Both of these conduits pass through the partition 17 or other division member which closes the inner or forward end of the sleeve 12 and terminate in open ends disposed within the chamber formed by the sleeve 12, the partition 17 and the louvered panel 16. The exhaust gas conduit 32 is located in the upper part of the chamber, and the air inlet conduit 34 is located below the conduit 32 in generally the same vertical plane. Both conduits are of uniform cross sectional area along their length, and the vent conduit 32 is of greater cross section so as to handle the greater volume of exhaust. The air inlet conduit, while projecting into the chamber, terminates forwardly of the exhaust conduit 32.

The conduits 32 and 34 are provided with separate baffle assemblies which in combination with their respective conduits and with each other direct the flow of exhaust gases and incoming air in opposite directions through the chamber. The baffle assembly associated with the vent conduit 32 includes a sleeve-like length of conduit 36 concentric with and surrounding the open end of the conduit 32 and radially spaced therefrom. A vertical plate 38 of about the same area as the cross section of the conduit 32 is disposed concentrically within the sleeve 36 at a position rearwardly of and directly opposite the open end of the conduit 32. The plate 38 may be supported in any convenient manner, as by spaced-apart angle brackets 40 which are secured to the edge of the plate 38 and to the inner surface of the sleeve 36, The sleeve 36 is supported from the vent conduit 32, as by spoke-like brackets 42.

The baffle assembly associated with the combustion air inlet conduit 34 includes a vertical plate 44 spaced rearwardly of the open end of the conduit 34. Preferably, the plate 44 is of greater area than the cross section of the conduit 34 and is constructed to direct air to the open end of the latter from below and from above. The latter feature is effected by two vertical flanges 46 which extend from the edges of the plate 44 forwardly to the partition 17 to which they are secured so as to support the plate 44.

The forward ends of the conduits 32 and 34, as already stated, communicate with the heater 22 so as to provide a continuous inflow of air and outflow of exhaust during operation. In the illustrated embodiment the forward ends of the conduits connect directly with the appropriate parts of the combustion chamber, the air inlet conduit 34 connecting with the lower end of the main combustion chamber 26 and the exhaust conduit 32 connecting with the plenum chamber 26a. Depending on the details of the construction of the heater 22 it may be necessary or desirable to incorporate additional shaped lengths of conduit to effect the connection of the forward ends of the conduits 32 and 34 to the outlet and inlet, respectively, of the heater 22, inasmuch as the latter may not be related so as to permit direction connection as in the illustrated embodiment.

A heat shield in the form of an inverted channel-shaped plate 48 is disposed intermediate the vent conduit 32 and the top wall of the sleeve for preventing overheating of the latter.

During operation of the heater 22 fresh air moves horizontally through the lower portion of the louvered panel 16, through the sleeve 12 and is then directed by the baffle plate 44 upwardly and downwardly into the open end of the inlet conduit 34, as illustrated by the arrows 50 in FIG. 2. The conduit 34 introduces the air into the lower part of the main combustion chamber 26 below the level of the burner tube 28 and about midway along the length of the chamber 26. Simultaneously, the hot, expanded combustion gas moves upwardly in the chamber 26, then rearwardly through the plenum chamber 26a into the exhaust conduit 32, thus producing a draft which creates the inflow of fresh air. The exhaust gas reaching the open end of the conduit 34 moves radially outwardly, then rearwardly through the annular passage between the plate 38 and the sleeve 36, as illustrated by the arrows 52, and finally out through the upper portion of the louvered panel 16 without mixing with the oppositely flowing fresh air.

When the air conditioner is operating, air circulates around the condenser coils 8 and then rearwardly through the panel 16 under the action ofa suitable fan. Generally, the fan will be located forwardly of the coils 8 and will cause ambient air to move into the chamber at the periphery of the mass of coils.

It has been found that the described configuration of the air inlet and exhaust outlet, that is, the use of the horizontal conduits 32 and 34 and their associated baffle arrangements in a common chamber, produces uniform flow of inlet air and exhaust gas while permitting the rear open end of the chamber to be fitted with a louvered panel, a grille or the like which is substantially flush with the outer surface of the wall 14. As previously stated, this feature is particularly desirable in a combination air conditioner-gas heater unit, because it allows all the parts which require direct access to the atmosphere (i.e., the air inlet, the exhaust vent and the condenser portion of the air conditioner) to be so located that the rear surface of the unit can be flush or substantially flush with the outer surface of the wall. Actually, the fact that the rear surface of the unit can be a single louver, grille or the like is advantageous even if, for any reason, the rear of the unit should have to project from the building wall, because in this case there is but a single projection rather than separate projections for the heater and the air conditioner. The aesthetic advantage of this feature is readily apparent where a plurality of units are spaced apart along a common wall, as in a motel.

Referring more specifically to the flow of inlet air and exhaust gas, it will be appreciated that the placing of the openended conduits 32 and 34 in a common chamber in order to permit the use of the louvered panel 16 inherently introduces the problem of achieving separate flow of inlet air and exhaust not only under quiescent atmospheric conditions but particularly under windy conditions. As might be expected, a wind blowing directly against the building wall is the most undesirable condition, because it tends to pressurize the interior of the sleeve 12, thereby tending to cause exhaust and inlet air to mix and to resist movement of exhaust out of the conduit 32. It has been found, however, that the conduit and baffle arrangement of the present invention overcomes these adverse tendencies. Specifically it has been found that when wind blows directly against the building wall, a high pressure zone builds up adjacent the building wall and adjacent the partition 17, the thickness of the zone being illustrated in FIG. 2 by the line 60. Since the inlet end of the air inlet conduit 34 lies in the high pressure zone and since the outlet end of the exhaust conduit 32 lies in a zone of lower pressure, the flow of air through the heater 22 in the proper direction is assured.

lclaim:

1. ln a gas-fired, wall-mounted space heater of the kind including a sealed combustion chamber disposed on the room side ofa building wall and having a combustion air inlet opening and an exhaust gas outlet opening arranged to provide inward flow of air and outward flow of exhaust by gravity, the improved inlet and vent construction which comprises: a housing defining a chamber disposed within the building wall and having a rearwardly-facing opening in communication with the atmosphere and a closed forward end adjacent the inner surface of the building wall; vertically-disposed, perforated panel means disposed across said opening and substantially flush with the outer surface of the building wall; a horizontal exhaust gas conduit communicating at one end with said outlet opening of said combustion chamber projecting through said closed chamber end and terminating in a rearwardly-facing open end in said chamber; a horizontal air inlet conduit communicating at one end with said inlet opening of said combustion chamber, projecting through said closed chamber end and terminating in a rearwardly-facing open end in said chamber at a location below and forward of said exhaust gas conduit; baffle means in said chamber and associated with each of said open ends for directing fresh air forwardly through said perforated panel means and into said inlet conduit and for directing exhaust gas rearwardly from said exhaust gas conduit outwardly through said perforated panel means while resisting the effect of wind on the flow of inlet air and exhaust gas, said baffle means including a vertical baffle plate disposed rearwardly of and opposite the open end of said exhaust gas conduit and a vertical plate disposed rearwardly of and opposite the open end of said inlet conduit and forwardly of the plate associated with said exhaust gas conduit.

2. Apparatus as in claim 1 wherein the baffle means associated with said exhaust gas conduit further includes a sleeve having a rear open end surrounding and spaced-apart from the open end of said conduit and surrounding the plate associated with said open end to define a generally annular passageway for the passage of exhaust gas.

3. Apparatus as in claim 2 wherein said sleeve has a forward open end spaced-apart from said closed chamber end.

4. Apparatus as in claim 1 wherein said baffle means associated with said air inlet conduit includes vertical wall means extending on opposite sides of said inlet conduit from the respective baffle plate forwardly to the closed chamber end to thereby direct incoming air to said inlet conduit in upward and downward directions, the vertical dimension of said wall means being at least as great as the vertical dimension of said inlet conduit. 

